While I haven't heard too much about the high rate of moisture absorption of Motul, I've read about having to change it more often. However I'd bet that is due to the "normal" use that people who actually use Motul are subjecting the fluid to(track days etc). Here is a thread about it on H-T(the dealership/source is well respected in the NSX community):
http://www.honda-tech.com/showthread.php?t=1612881
I'd say sticking with the Motul over long periods of time is just fine for 99% of the people out there. But if you are road coursing it time after time, I'd change it more often.. Like you would with ANY fluid. So no loss if you ask me.